OREANDA-NEWS. March 24, 2015. South African share prices eased slightly on Monday with heavy hitters such as MTN Group trading ex-dividend and despite higher copper prices boosting producers of the metal.

Africa's largest telecoms provider MTN gave up the most value on the blue chip list when it lost 5 percent because it started trading without rights to the latest dividend.

The benchmark Top-40 index shaved off 0.2 percent to 46,480 and the All-share gave up 0.1 to 52,559.

Johannesburg's mining index was up 1.7 percent led by African Rainbow Minerals, which added nearly 4 percent as copper prices rose to their highest level in more than two months.

Copper is riding on the weakening dollar, which has been on the back foot on expectations the United States will delay an interest rate hike. The infirm dollar boosts the purchasing power of commodity buyers paying with other currencies.

While positive for copper producers, the weak dollar is a negative for other South African mineral exporters as it slashes profits when overseas earnings are brought home.

"It's very mixed. There are certain shares still recovering in a quite a big way, in particular some of the mining shares," Afrifocus Securities' Ferdi Heyneke said.

On the downside, insurer Discovery gave up 3.3 percent as its 90-rand-per-share rights issue opened.

Decliners outnumbered advancers 182 to 131 with 42 shares unchanged, according to preliminary bourse data. Activity was relatively brisk with around 186 million shares changing hands, above last year's daily average of 183 million shares.